This invention relates to lead wires for use with stereo pick-up devices and tone arms and in particular to lead wires and arrangements thereof for connecting the pick-up device to the stereo amplifier.
Conventionally the pick-up for a stereo record playback system simply has the lead wires randomly passing through the tubular tone arm to lead the outpt signal from the pick-up cartridge to the amplifier. Referring to FIG. 1 for this, 1 is a tubular tone arm, 2 is an arm holder, 3 is a balance weight, and 4 is an arm support, which comprises a slide pipe 5, rotor shaft 6, and bearings 7. 8 is the connector for the cartridge, 9 is a terminal connection to the amplifier, and 10 generally indicates lead wires. Lead wires 10 extend from connector 8 through arm 1, are turned at 12 in the direction of support 4, and are directed to terminal 9 through support 4. In FIG. 2, L+ stands for left channel positive, L- for negative, R+ for the right channel positive, and R- for negative, the channels being wired separately. The distance from connector 8 to terminal 9 is usually as long as 30 cm. Consequently, the crosstalk characteristic between the left and right channels deteriorates at higher frequencies due to mutual interference.
In order to prevent the mutual interference, some arms are designed so that the pipe of the arm is divided in the axial direction into two chambers with a separating plate for shielding, the lead wires for each channel being passed through the respective chambers. And, in another, spacers are inserted so that the lead wires in the pipe are kept apart. However, in these cases, the arm becomes heavy, which is likely to have an undesirable effect on the rotating motion of the arm.
In order to eliminate the above-mentioned shortcomings, tone arm lead wires that are formed into one by alternately abutting the positive side lead wires and the negative side lead wires are described in Japanese Utility Model Publicatiion No. Sho-50 128002 and it has been stated that crosstalk characteristics were improved.